Flooding in Northeast China last month that killed 74 people, with another 71 still missing, has triggered fears among experts about the country's infrastructure and industrial zoning.

Heavy rains, which have battered Jilin province since July 20, have resulted in severe damage to 677 bridges and 51 reservoirs and affected almost 4.6 million people.

Soldiers work to fix the damaged water pipelines in suburban Tonghua. Four pipes connecting the city with a local water filtering plant were destroyed in floods caused by torrential rain. [China Daily]

More than 784,000 resident were evacuated from the danger zones across the province by authorities.

Water and electricity supplies in several cities and counties were either disrupted or completely severed for days. Urban planning experts also blamed shortages in tap water supplies on the number of pipes destroyed by the rushing floodwaters.

Xie Yingxia at the China Academy of Urban Planning and Design said extra investment in city infrastructure would prevent similar disasters in extreme weather conditions or natural disasters.

"If we had backup water supplies and pipelines, this wouldn't have happened and entire cities would not have been disrupted," she said.

As the country has witnessed rapid development and urbanization, Xie added, projects above ground have overshadowed the urgent need to update cities' underground pipe and sewer networks.

"It (the flooding) has shown that there is a problem," Yang Hongshan, an associate professor with Renmin University of China, said in an interview with China Central Television (CCTV), the State broadcaster.

He argued that the threat of flooding should be taken into consideration when new infrastructure projects are launched, while overall standards should be improved to ensure any supply lines are strong enough to withstand a major catastrophe.

More than 300 companies were forced to halt or slow production amid the continuous downpours. Floodwaters also swept 7,000 barrels filled with chemicals into Songhua River, sparking serious concerns for a waterway that acts as a major source of drinking water for Jilin.

Environmentalists said after the incident chemical plants on the upper reaches of rivers and other waterways pose a serious threat to ecology nationwide.

"The zoning of chemical industries in China was fixed several decades ago but today we've realized that it was a big mistake," said Ma Zhong, dean of school of environment and natural resources at the Renmin University of China. "The pollution in Songhua River is a typical example."

Ma told reporters with Southern Weekly, a newspaper based in Guangzhou, that "a lot of pollution is closely related to the location of industrial areas".

As industries develop and continue to move from downstream base in the east to upstream plants in the mid-west, the environment problems will worsen, he stressed.

On Aug 5, the Ministry of Industry and Information Technology issued an emergency statement, urging local governments and enterprises to prevent the risk of environmental hazards during the flood season.